Observations on the incidence of plant parasitic nematodes in grassland in England and Wales

Soil samples taken from one- to four-year-old swards of white clover and perennial ryegrass at 34 sites, and from older clover/grass swards at 56 sites in England and Wales, were examined for plant parasitic nematodes. Stolons of white clover from 46 of these sites were examined for nematodes. Clover cyst nematode ( Heterodera trifolii ) and white clover stem nematode ( Ditylenchus dipsaci ) were found in 62% and 41% of sites respectively. The grass cyst nematode ( Punctodera punctata ) was present in 56% of 71 sites examined, and other grass cyst nematodes ( H. bifenestra and species of the H. avenae group) occurred in 13% and 17% of sites. Two root-knot nematodes were found, Meloidogyne naasi and M. hapla, in 15% and 4% of the samples examined. Migratory nematodes were extracted from 63 samples, and spiral, pin and lesion nematodes were found in more than 90%. Stunt nematodes were less frequent (65%) and criconematids (19%) were found relatively infrequently. The significance of these observations to grassland productivity is discussed.